Shader programming with ShaderLab and CG in unity

Question

I am trying to learn Shader programming using ShaderLab and CG in UNITY. Is there any step by step FREE guide (videos/book/tutorial)available ?

Please don't recommend me NVIDIA CG tutorials (it is extremely descriptive and difficult to understand) and unity official site (there is no description only code)

I'm searching and learning Shader programming form last 3 days still didn't find any good resource and It is my observation/perception that it is difficult to learn although I have some experience and good understanding of C# and Javascript programming but facing much difficulty to learn it.

Answer 1

I don't know any really good free resources, but I can recommend you this really good book. It is worth buying it.

Answer 2

I've created a resource for getting started with shaders:

http://wiki.unity3d.com/index.php/Getting_Started_with_Shaders

Be warned, this was three years ago -- I have since moved away from Unity3D, and it doesn't look as though anyone else has updated it since.

As it is a wiki, I encourage anyone to update it with resources they have found useful.